The overall goal of this project is to acquire new information regarding temporal bone pathology in human infants and children. The objectives of the proposed work include the following specific aims: (1) investigation of inner ear pathology associated with middle ear infection; (2) study of temporal bone abnormalities in infants with congenital cardiovascular malformations; (3) assessment of vestibular pathology, with particular emphasis on the otoconial membranes of the saccule and utricle. Data from patient histories and autopsy findings will be correlated with the results of temporal bone examination in all cases studied. Temporal bone specimens obtained at autopsy will be processed by microdissection or by serial sectioning after embedding in celloidin or plastic. The material will be studied using a combination of light and electron microscopic techniques. In addition to providing new insights into the pathophysiology of ear disease, the data obtained will provide an objective basis for treatment of otitis media in hildren and aid in management of hearing loss associated with developmental malformations.